Catapult™ Using

Making Connections
As with all audio systems, it is good to turn your audio system off or turn system levels down to zero before making connections. This will avoid connection or power-up transients from damaging more sensitive components such as tweeters.

Using standard TX4 and RX4 (non-isolated) modules
To use the Catapult in the simplest form, connect the TX4 and the RX4 together using Cat 5 or Cat 6 cable. In order to pass 48V phantom power to feed your condenser mics or active direct boxes, the cable must have a shield. If you are transmitting line level signals, the shield is not required due to the twisted pair configuration, but it will still be beneficial as shielded cables are less susceptible to noise. As the twisted pairs are tightly wound together in a compact jacket, it's a good idea to send similar level signals together over the same wire as this will reduce crosstalk from higher signal levels (such as +4dB line levels) polluting lower output signals (such as -30dB mic levels). TX and RX modules are equipped with two sets of XLRs to enable greater connectivity. This is basically a simple Y-jack that can be handy in certain situations.

Using Mic Level TX4M and RX4M isolated modules
These modules are typically employed when splitting a mic signal between two mixers. Although the transformers may be ordered inside either the transmit TX4M or receive RX4M boxes, these are usually put inside the transmit box as this affords greater flexibility.

For instance, you may be doing a gig where your stage mics need to be sent to a monitor mixer by the stage, as well as a distant front-of-house mixing console. The TX4M would allow you to directly connect your microphones to the FOH console so it can provide phantom power, while high-performance Eclipse transformers keep the monitor mixer isolated and prevent ground loops.

You can also use the same TX4M module to isolate the microphones to feed a separate recording system. Transformers are truly amazing devices that surprisingly come in handy in all types of situations.

Using Line Level TX4L and RX4L isolated modules
As described above, transformers eliminate noise. These problems are often most predominant in situations where the two connection points are distanced from each other. In these setups, the electrical circuits are often on different power legs which can sometimes cause noise to enter the PA system. Isolating the signal allows the audio to pass while blocking the stray DC voltages that can disrupt the system.

Line level isolators are usually positioned at the receive end (RX4L) of the system as this generally affords greater flexibility. If using the Catapult as a return snake for monitors or from a crossover, isolating the stage from the front-of-house (FOH) can save hours of trouble shooting!

Simply connect the output from your console to the Catapult and the isolated outputs to your amp racks or powered speakers. The Eclipse transformers inside are capable of handling up to 15dB without distortion. If you like, you can use the non-isolated outputs to feed another piece of equipment such as a recorder.

Lifting the ground
Each Catapult module is equipped with a ground lift switch. Set this in the 'out' position. Once connected, if you hear noise, try lifting the ground at one end or the other. It is usually best to lift the ground at the transmit end as it will generally be connected to a microphone whereas the receive end will be connected to an electronic device such as a mixer that is properly grounded to the electrical system for safety. However, lifting the ground will disconnect phantom power, which means that condenser mics or active DI boxes will not work.